n-android

Asus Zenfone Unknown Baseband & IMEI Null Final Solution

Asus Zenfone Unknown Baseband & IMEI Null Final Solution

Flash your phone with Stock Zip even RAW file. If same issue then try to restore network part.

How would you backup and restore...?

Instance of.. ZenFone 5 
Backup 

Code:
adb shell
su
dd if+dev/block/mmcblk0p3 of=sdcard/mmcblk0p3.img

Credits: AzimBahar and GSMDevelopers Team

Restore

Code:
adb shell
su
dd if+/sdcard/mmcblk0p3.img of=/dev/block/mmcblk0p3

There is nothing more remain to do Software. If still same then you need to try Hardware.